WASHINGTON — The Air Force is launching an ambitious campaign to repair flaws in its nuclear missile corps, after recent training failures, security missteps, leadership lapses, morale problems and stunning breakdowns in discipline prompted Defense Secretary Chuck Hagel to demand action to restore public confidence in the nuclear force.

Air Force leaders are planning to offer bonus pay to missile force members, fill gaps in their ranks, offer a nuclear service medal and put more money into modernizing what in some respects has become a decrepit Minuteman 3 missile force that few airmen want to join and even fewer view as a career-enhancing mission.

The potential impact of these and other planned changes is unclear. They do not appear to address comprehensively what some see as the core issue: a flagging sense of purpose in a force that atrophied after the Cold War ended two decades ago as the military’s focus turned to countering terrorism and other threats.

Even so, some analysts are encouraged by these initial Air Force moves.

“I think this is a step in the right direction,” said Dana Struckman, a retired Air Force officer who commanded a Minuteman 3 missile squadron at Minot Air Force Base in North Dakota in 2003-05. “I think it will make a difference.”

Driving this effort is Air Force Secretary Deborah Lee James, who took over as the service’s top civilian official in December amid a series of embarrassing lapses by the men and women who operate, support and lead the fleet of 450 intercontinental ballistic missiles, or ICBMs, based in North Dakota, Montana and Wyoming.

The missiles are armed with nuclear warheads, ready for launch on short notice any day, any hour.

In January, after visiting a Minuteman 3 base, Hagel declared, “We know that something is wrong.” He ordered a pair of comprehensive reviews to identify what was amiss and to recommend solutions. Both reviews missed their initial deadlines for completion, and Hagel has said little publicly about it in recent months.

The cascade of bad news began in May 2013 when The Associated Press revealed that a group of ICBM launch officers at Minot Air Force Base had been stripped of their authority following a poor inspection result and other problems. The AP also disclosed that the deputy operations commander at Minot had complained in an internal email of “rot” in his ranks — an assessment that aired a range of morale and other behavioral, training, leadership and security problems that later emerged at the ICBM bases in Wyoming and Montana.

In October the two-star general in charge of ICBMs was fired for drunken behavior while on official business in Russia, and in November the AP revealed an unpublished study that found evidence of “burnout” among missile launch officers and cited elevated rates of personal misconduct within the ICBM force.

For months Air Force officials insisted that the morale issues and other problems amounted to nothing more than commonplace gripes and isolated, correctable goofs. James, however, took a different approach.

In January, just weeks after taking office and days after the discovery of an exam-cheating scandal among nearly 100 launch crew members in the 341st Missile Wing at Malmstrom Air Force Base in Montana, James declared herself “profoundly disappointed,” and announced that the ICBM force was in need of closer scrutiny. She visited all three ICBM bases and said afterward the problems are “systemic,” not isolated.

Also in January, the Air Force disclosed that three ICBM launch officers were among those implicated in a criminal investigation of drug use or possession — a probe that remains active. And in March it announced it was firing nine officers in leadership positions at Malmstrom and one, Col. Donald Holloway, at F.E. Warren Air Force Base, which is headquarters for the organization in charge of the entire ICBM force.

Since then the Air Force has developed and begun publicizing internal changes aimed at fixing what ails the ICBM force, although the two reviews that Hagel ordered in February are not yet complete. It’s unclear how the Air Force’s proposed changes will be squared with whatever recommendations emerge from Hagel’s reviews.

Among the more dramatic and potentially important moves, James has recommended to Hagel that he put a four-star general in charge of the nuclear Air Force, including the ICBM and bomber fleets, thereby elevating its status and clout inside an Air Force more focused on air, space and cyberspace missions. A three-star general is currently running the force. Raising the rank to four stars will require approval by Congress.

Such a move would put the Air Force more in line with the Navy, whose nuclear force is overseen by a four-star officer, Adm. Terry J. Benedict, who has an eight-year tenure and reports directly to the top Navy admiral.

The Air Force also plans to offer extra pay to attract and keep people in the missile fields. It’s an idea that has been kicked around for years but never implemented, to the consternation of many airmen. Newly trained missile launch officers, known as missileers, will get a yearly bonus throughout their tour, according to Lt. Col. John Sheets, an Air Force spokesman. He said the dollar amount is yet to be decided. Current missileers, as well as security force members and others in the missile fields, will get monthly bonuses, he said.

Flaws in the Air Force’s nuclear management have been apparent for years, according to Michelle Spencer, who led a year-long study of the nuclear Air Force and concluded in a report published in January 2012 that numerous attempts since 2008 amounted to “movement without direction.” At its core, she wrote, are questions about the Air Force’s ability to develop, sustain and value nuclear expertise.

“Without answers to these fundamental questions,” she wrote, “the Air Force nuclear enterprise remains on the same trajectory as it has been for the last two decades — in ever-increasing decline.”

Spencer’s study, which was requested and funded by the Air Force, also found that senior Air Force leaders were getting “false or distorted information about the reality on the ground” in the nuclear force. That distortion permitted small problems to grow into big ones and reflected cynicism about the nuclear mission, she wrote.

Spencer said James appears to have made inroads against that problem, “but I’m sure they haven’t solved it.”